Presenter's biography

Biographies are supplied directly by presenters at OFFSHORE 2015 and are published here unedited

K. Gkarakis received his Bachelor’s in Energy Technology Engineering in Greece and his MSc in Energy in Scotland, UK. He is currently wind energy consultant in RES companies. Also, he is research engineer in Technological Educational Institute of Athens (TEI Athens). He spent 12 years worked at different RES companies and his primary research lie in the fields of i) wind potential and energy studies, ii) site compliance studies, and iii) evaluation of reanalysis and mesoscale datasets in the investigation of the longterm wind climate. He has more than 45 papers, presentations and announcements in scientific journals conferences and workshops.

Abstract

Use of mesoscale wind data: contribution to a better and cheaper resource assessment for offshore windfarm development?

Introduction

The offshore wind development has reached 7,3GW installed capacity on July of 2014 in Europe. In terms of installed capacity four countries (UK, Denmark, Belgium and Germany) have a percentage of approximately 90% of the total. The offshore windfarms have mainly installed in North and Baltic Sea (total 84%). In the Mediterranean Sea, there are only planned offshore windfarms and the project activity is quite low in the countries of South Europe. Also, the financial crisis and the latest legislative changes have created more difficulties in offshore development, especially in countries in Southern Europe.

Approach

One of the main factors for a development of an offshore windfarm is the forecasting of the wind resource, especially in Mediterranean Sea where the exploitable wind resource is lower than other seas. The objective of this study is the presentation and evaluation of mesoscale wind data for the wind resource assessment of sea areas, especially in Mediterranean Sea. For this aim, EMD ConWx data used and compared with data from two seashore masts and two buoys.

Main body of abstract

The cost of installation an offshore meteo mast is high (1-3 million Euro) and isn’t financial affordable or preferred at the first stages of technical development and licensing of an offshore windfarm. So, the use of mesoscale data and mesoclimatic maps is incomparable cheaper solution for the primary wind resource assessment.
EMD ConWx are mesoscale dataset which are modeled and computed in-house in ConWx and EMD. The model is run at high spatial resolution of 0,03° x 0,03° (appr. 3x3km) with 1h temporal resolution. Interim data from ECMWF are the global boundary data. The temporal coverage is from 1993 until present and the available data are from the heights of 10-24-50-75-100-150-200m agl.
The mesoscale data have been compared with the measurements of two seashore meteo masts (10 & 25m agl) – 1 year (10min measurements) and two buoys measurements (3,3m asl – 12years) – (3h measurements) which are operated by Hellenic Centre for Marine Research (Poseidon System). Area of the study is the Northern Aegean Sea, Greece where there is remarkable offshore wind projects development (more than 2GW).
The strength of the relationship has been measured by means of correlation coefficient R using the matrix MCP method (CRES WindRose and EMD WindPro software). Concurrent data at common temporal resolution and monthly values have been used.
The ConWx data show a high spatial and resolution which allows a better representation of the local wind climate but the issue of the thermal driven wind gives a some lower predictability, especially in coastal zones.

Conclusion

There is experience using mesoscale data for primary assessments for under development offshores mainly in the Baltic Sea, North Sea and Irish Sea, where it is presented quite high correlation for offshore wind with met masts in the area, this paper gives the opportunity to evaluate the use of mesoscale data for wind resource assessments in Mediterranean Sea, though comparison with measurements from seashore mast and buoys.
In general, this paper gives the opportunity to study real offshore winds in Mediterranean Sea and to examine the usefulness of the mesoscale data for the primary wind resource assessment for offshore windfarms.

Learning objectives
Evaluation of the state-of-the-art long-term mesoscale wind database and the comparison with real measurements, at the stage of primary wind resource assessment, provides useful information to the research and business community of wind energy. This study contributes to a better and cheaper resource assessment for offshore windfarm development, especially in countries where offshore wind energy is at the first steps.

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